Polydopamine microcapsules loaded Ag nanoparticles for catalytic reduction of organic pollutants

We demonstrate a simple approach for fabricating polydopamine microcapsules decorated with silver nanoparticles (Ag@PDA MCs) as highly efficient catalysts for water purification . Polydopamine microcapsules (PDA MCs) were formed on the MnCO 3 template from self-polymerization and the removal of template under mild EDTA solution, followed by in situ reduction of Ag + by PDA and growth of monodispersed Ag nanoparticles . Under optimized conditions, the Ag@PDA MCs exhibits 41.56 wt% of Ag loading contents and superior catalytic performance for the degradation of organic pollutants with rate constant of 2.93 min -1 for methylene blue and 1.03 min -1 for 4-nitrophenol. The excellent catalytic activity can mainly be ascribed to high surface roughness of microcapsules, high Ag loading ratio, and uniform distribution of Ag nanoparticles . In addition, this catalyst can be recycled for five times with degradation efficiency higher than 98%. The Ag@PDA MCs possessed fast reduction rate, high catalytic activity, and good recyclability as well as facile preparation and easy separation, showing great potential for the application in wastewater treatment .